Iran’s nuclear chief declared that his country has developed a new generation of centrifuges 15 times more powerful than those currently being used to enrich uranium, and said it might resume enrichment to 60% if necessary.

“We unveiled a new generation of centrifuges that surprised the Westerners,” said Ali Akbar Salehi on Monday. “This new machine is 15 times more powerful than the previous generation,” he claimed, according to Iran’s state broadcaster IRIB.

Salehi added that the development did not violate the November 24 Geneva interim agreement between Iran and six world powers that has imposed curbs on Tehran’s nuclear drive. “We successfully argued that this was allowed within the research and development article in the agreement,” Salehi said.

Talks between Iran and the six powers — the United States, Russia, China, Britain, France and Germany — on a long-term, “comprehensive” accord are due to start in Vienna on February 18. Ahead of them, Israel’s Minister for Strategic Affairs is to lead a delegation for talks with the chief US negotiator with Iran, Under Secretary of State for Political Affairs Wendy Sherman.

Sherman last week told a Senate hearing that Iran’s ballistic missile program would be addressed in the comprehensive deal.

But on Monday Iran’s deputy foreign minister Abbas Araqchi, who is also a senior Iranian nuclear negotiator, said “the defense-related issues are a red line for Iran.”

“We will not allow such issues to be discussed in future talks,” he said.

Sherman also argued that Iran does not require an unfinished heavy water reactor in Arak – which could one day produce plutonium as a by-product – nor the underground Fordo uranium enrichment site for its civilian nuclear program.

But another Iranian nuclear negotiator, Majid Takhte Ravanchi, on Monday reiterated that Iran would not accept the closure of “any of its nuclear sites.”

Last week, Salehi said Iran could make changes to Arak’s design to produce less plutonium and “allay the worries.”

Prime Minister Benjamin Netanyahu lambasted the US and the international community for the Geneva deal, which he called a “historic mistake,” and he is demanding that Iran’s entire “military nuclear” capability be dismantled under a permanent accord. US President Barack Obama, by contrast, has said he could envisage Iran being left with a heavily supervised enrichment capability under a permanent deal.

Iran currently has nearly 19,000 centrifuges, including 10,000 of the so-called first generation being used to enrich uranium. Some 1,000 second generation machines, three to five times more powerful, have been installed but are not in service. Under the November deal, Iran cannot increase the number of its centrifuges.

Salehi did not say when the new centrifuges would become operational, but said a first machine was to be delivered to a medical centre in Karaj, west of Tehran, “within two or three months.”

In a recent interview with The Times of Israel, former Israeli Ambassador to the US Michael Oren warned that Iran was continuing to develop its centrifuges, and that more sophisticated models would enable it to speed more quickly to nuclear weapons if it chose to try to break out to the bomb. “If the talks break down,” he warned, “and you [the Iranians] quickly install your additional 9,000 centrifuges, among them the IR2s, which really give you [the equivalent of] about 24,000 centrifuges. And you have a stockpile [of enriched uranium]. And maybe you’ve done some research and development, that actually gives you some [centrifuges] closer to an IR3, which has an even higher rate of accumulation than the IR2s, how long is it going to take you [to break out]?”

In his remarks Monday, Salehi also said that despite the current halt in Iran’s uranium enrichment above the 5% grade, as agreed in the Geneva interim deal which took effect in late January, Iran has not and will not give up its right to enrich uranium to the 20% grade and may even resume enrichment to 60% if needed.

“We have met our needs to the 20-percent-enriched fuel (for the Tehran research reactor and medical purposes) and we have enough fuel, but we have not lost our right to produce 20 percent fuel,” he said, according to the Fars news agency.

He claimed Iran was entitled to enrich uranium to any level it wanted, and said, “We have the ability to enrich uranium at 60 percent grade if one day we need it for peaceful works.”